Fixing devices are used to fix toner to media in electrophotographic imaging systems. The fixing process involves the application of heat to the media and toner by the fixing device. To reduce power consumption, the power supplied to the fixing device is typically reduced from the level applied during fixing, when the fixing operation is not performed. The time varying application of power to the fixing device results in successive cycles of heating and cooling. The successive cycles of heating and cooling can cause failures from thermally induced mechanical stresses in the fixing device. A need exists for a fixing device having reduced levels of thermally induced mechanical stresses.